Improve route changes handling under guard/spork

Guardfile

@@ -3,7 +3,6 @@ directories %w[app config spec]
 guard :spork, rspec_env: { RAILS_ENV: 'test' } do
   watch('config/application.rb')
   watch('config/environment.rb')
-  watch('config/routes.rb')
   watch(%r{^config/environments/.+\.rb$})
   watch(%r{^config/initializers/.+\.rb$})
   watch('spec/spec_helper.rb')
@@ -13,6 +12,7 @@ end
 guard :rspec, cmd: 'bundle exec rspec --drb -f doc' do
   watch(%r{^spec/.+_spec\.rb$})
 
+  watch('config/routes.rb')           { 'spec' }
   watch('spec/spec_helper.rb')        { 'spec' }
   watch(%r{^spec/support/.+\.rb$})    { 'spec' }
   watch('spec/factories.rb')          { 'spec' }